The thyroid gland is a long butterfly-shaped gland in the neck. It’s about two inches long and contains two lobes, or sections, one on each side of the windpipe.

The main role of the thyroid is the production of hormones that regulate metabolism and many of the body’s processes. Two of the main hormones are T4 (thyroxine) and T3 (trilodothyronine). T4 accounts for 90 percent of thyroid hormone production. It’s converted in the liver into T3, the active form of the hormone.

Overall, the production of thyroid hormones is controlled by the pituitary gland. When concentrations of thyroid hormones drop, the pituitary gland releases thyroid-stimulating hormone (TSH), which in turn, stimulates the production and release of T4 and T3.

Thyroid Problems

Hyperthyroidism is a condition in which the thyroid gland releases too much thyroid hormone. The excessive hormones cause the body’s metabolism to speed up and can lead to increased heart rate, nervousness, tremor, weight loss, insomnia, vision problems, menstrual irregularities and dry, irritated or puffy eyes. In hypothyroidism, the thyroid doesn’t produce enough thyroid hormones. Metabolism slows and patients may experience weight gain, fatigue, forgetfulness, dry skin, heavy menstruation, mood swings, intolerance to cold and constipation.

According to the American Association of Clinical Endocrinologists, about 27 million Americans have either hypothyroidism or hyperthyroidism. 80 percent of patients are women. The risk for hypothyroidism is higher in older people because thyroid production tends to decrease with age. By 60, about 17 percent of women and 9 percent of men have low thyroid production.

Hashimoto’s Thyroiditis

The most common cause of thyroid disease in this country is Hashimoto’s thyroiditis. It’s caused when the immune system mistakenly attacks and destroys the thyroid gland, causing inflammation and a decrease in thyroid production. In addition to symptoms of hypothyroidism, patients may develop a goiter, an enlargement of the thyroid gland (often seen as a bulge in the neck). In severe cases, Hashimoto’s thyroiditis can lead to depression, heart failure, myxedema coma (a life-threatening condition) and, in pregnant women, birth defects. Hashimoto’s thyroiditis is seven times more common in women than in men.

Dealing with Thyroid Problems

Andre Garabedian, M.D., is a Family Practitioner at the Fibromyalgia & Fatigue Center in King of Prussia, PA. He says many of the symptoms of thyroid disease (like nervousness or fatigue, weight gain and dry skin) are vague and often dismissed as minor annoyances or caused by other factors. If thyroid disease is suspected, there are several blood tests that can be done.

Garabedian says doctors most often screen for thyroid disease by looking at TSH and T4 levels. But even if the results fall within “normal” levels, thyroid disease shouldn’t be ruled out. Garabedian believes cut-off levels for thyroid disease screening should be much lower than they are. Therefore, if thyroid disease is still suspected, patients should have a thyroid antibody test. This test measures the levels of common antibodies that can attack the thyroid gland. The presence of these antibodies in a patient with signs of hypothyroidism is an indication of Hashimoto’s thyroiditis.

Another test that may be considered is called reverse T3. When the body converts T4 into T3, most of the T3 is changed into an active form of the hormone. However, some of it gets converted into reverse T3, an inactive form of T3 that can’t drive metabolism. So, if T3 levels are within normal range, but much of it is in the form of reverse T3, the test results will appear to show “normal” thyroid production. Garabedian says many physicians are unfamiliar with reverse T3 and don’t know there is a separate test for it.

Once a patient has received a diagnosis, proper treatments can be started. Patients who make too much thyroid hormone may be treated with medications or radiation therapy to slow production of thyroid hormone. In some cases, part or the entire gland may be removed. Patients with hypothyroidism often require life-long thyroid replacement therapy. Finding the right dose can be tricky because the level of need changes. So patients must have regular monitoring to ensure they are getting the right amount of replacement (and not too much). For general information on thyroid conditions, diagnosis and treatment:

American Association of Clinical Endocrinologists

American Thyroid Association

The Hormone Foundation

For information about thyroid lab tests: American Association for Clinical Chemistry, Lab Tests Online.